Equipo de la información:

The Fluke Model 1900A is a 5 Hz to 80 MHz mul-
tiple-function counter capable of making frequency, period,
period averaging and totalize measurements. In the frequency
mode, resolution is manually selectable at 0.1 Hz, 1.0 Hz,
10 Hz and 100 Hz. in the period averaging mode, the number
of periods averaged is manually-selectable at 10°, 101, 102
and 103 periods. Automatic selection of resolution and
number of periods averaged (autoranging) is also provided to
automatically select the optimum range for a particular
input signal. However, the 100 Hz resolution and 103 periods
must be manually selected.
1 -3. The measurement display is six digits, light-emit-
ting-diode-type (LED) with leading-zero suppression and
automatic decimal point positioning. Annunciators are provided
to indicate measurement units (kHz, MHz, milliseconds and
microseconds) and also overflow when the capacity of the
display is exceeded. All displayed information
is also available, in parallel BCD format, at a rear-panel
connector when the unit is equipped with an optional Data
Output Unit (DOU).
1-4. The Model 1900A is equipped with a selectable 1 MHz
low-pass filter for use in electrically noisy environments,
and a selectable 10:1 attenuator for use with high- level
inputs. A self-check mode of operation is provided to verify
overall performance of the unit. Power requirements are 100,
115 or 230 volts at 50 to 400 Hz for the line- powered
version. An optional battery-powered version, Model
1900A--Ö1, provides for use away from ac power lines and is
equipped with rechargeable nickel-cadmium batteries. The
battery-powered version also operates from the ac lines, but
only at the power line frequency and voltage specified on
the bottom of the instrument.